A number of multilayer microfluidic devices capable of performing electrophoretic separations and fluidic manipulations (mixing, reacting, piping and valving) have been demonstrated.1 To add functionality, hybrid microfluidic-nanofluidic devices are being developed that exploit the physical dimensions of nanoscale pores in nanocapillary membranes to allow a unique set of transport capabilities.2 In particular, a number of reports detail the use of crossed microchannels made in poly(dimethylsiloxane) (PDMS) that are vertically separated by a thin membrane containing a large array of nanocapillaries3 that permits a variety of sample manipulations, including: nanofluidic gated injection of analytes and electrophoretic separation,4 the mixing and reaction of two fluid streams,5 the collection of a specific electrophoretically separated band,6 and the separation of a sample based on mass (or molecular size).7 
Recently, there have been important advances in polymeric microfabrication. One advance is a modified transfer process,8 where each layer is processed as if it were an independent rigid substrate, which is then transferred, aligned, and bonded to a chip. The layer is then subsequently released from the carrier. Another advance is contact printing of an adhesive using elastomeric stamps. While elastomeric stamps have been used to contact print monolayer inks,9 thin metal films,10 and liquid polymers,11 the use of contact printing in microelectromechanical (MEMS) device fabrication to pattern layers as thick as 1 μm, as in the adhesive layer printing of benzocyclobutene for wafer level bonding,12 is relatively recent. PDMS stamps are widely used for contact printing due to their ability to conform to the surface to be printed upon, as well as their ability to be “rolled” onto that surface without trapping bubbles and particles at the interface.13 Typically the surface of the PDMS needs to be modified so that it wets and then transfers the compound being printed.